EU referendum: Conservative grassroots back top Tories behind Brexit campaign for new leader

'Leave' spokesmen Michael Gove and Boris Johnson are among the favourites to succeed CameronGetty/Reuters

David Cameron's successor as Conservative leader should be a top Eurosceptic, according to the party's grassroots. Justice secretary Michael Gove, outgoing Mayor of London Boris Johnson and former defence secretary Liam Fox are the leading three favourites to take the top job among Tory activists.

The Conservative Home poll will be a blow to chancellor George Osborne, who reportedly has ambitions to take over from Cameron when the prime minister steps down before the end of 2020. The April survey put Gove in front on 26%, with Osborne's rating dropping to 9%.

The findings come after Osborne faced a rebellion over his 2016 Budget because of planned cuts to disability benefits. The row led to the dramatic resignation of Iain Duncan Smith as work and pensions secretary, leaving Cameron's administration in crisis.

"I hope as the government goes forward you can look again, however, at the balance of the cuts you have insisted upon and wonder if enough has been done to ensure 'we are all in this together'," Duncan Smith wrote in his resignation letter.

The results come as the referendum on the UK's membership of EU nears. Cameron's cabinet is split over the historic ballot, with the likes of Gove and Northern Ireland Secretary Theresa Villiers backing a Brexit at the 23 June vote.